BMS shutting off system power when over voltage?

[HRTKD]

It may not matter, but how many amps are you getting into the BMS/battery from the solar charge controller?
Do you have other charge sources that you can test this with?
Is there a single battery in this setup?
How many amps do you REALLY need out of the BMS?

I think it's beyond time to replace the BMS. The high amps sounded good, but the inability to program the BMS is no good.

 

[Pincones]

It may not matter, but how many amps are you getting into the BMS/battery from the solar charge controller?
Do you have other charge sources that you can test this with?
Is there a single battery in this setup?
How many amps do you REALLY need out of the BMS?

I think it's beyond time to replace the BMS. The high amps sounded good, but the inability to program the BMS is no good.

Our array is 750 watts. In this off season it doesn't bring in more than 30amps in full sunshine. So it's not getting more than 30 amps from the array when it kicks off.
In the dark winter months we use a 60amp converter and use the generator to charge the battery. So the BMS spent the winter feeding 60 amps from the converter into the array and had no problems.

Yup, just one 12v pack of 4 cells.

We don't really "need" more than 100 amps. We've discussed downsizing to a new inverter (just for good measure) to 1,000 watts or so, so we can get by with a 100amp BMS. I got this 400amp-output inverter because if we plug something power-hungry into the house (blender on high, shop vac, etc) it could top it out and actually suck 300+ amps through the inverter momentarily. We rarely use these big appliances, and these days we just use them on the generator. The smaller inverter would be and extra measure of safety so it can't pull more than the BMS can deliver.

 

[HRTKD]

If you cut off the solar charge controller and switch to the converter, are you seeing the same voltage fluctuation behavior?

 

[Pincones]

If you cut off the solar charge controller and switch to the converter, are you seeing the same voltage fluctuation behavior?

We haven't tested that. It's been so sunny we haven't needed the converter! We'll fire it up and see what happens. What's the implication there- the CC itself possibly being bad if the converter creates a steady voltage?

 

[HRTKD]

We haven't tested that. It's been so sunny we haven't needed the converter! We'll fire it up and see what happens. What's the implication there- the CC itself possibly being bad if the converter creates a steady voltage?

Might as well rule out the solar charge controller as long as we're troubleshooting. As I recall, you measured the voltage between the solar charge controller and the BMS and it was steady. So the solar charge controller shouldn't be the problem.

 

[grd]

A couple of amateur comments because having a bit the same issues. Or was. Loose connections! Posted this site about those circuit breakers. Stay away from them. Automotive and not up to the job especially 48 v banks because they dont have high enough voltage rating.
I am blaming this CCA crap wire, if crimping you really need the right tool to get a super tight joint.
My inverter is switching off (batvoltmax) when full sun and bank hits max. Its SMA 6H and doesnt do lifpo4 and cant help wonder if that is the issue. You can manually set the sma for different charge rates but it doesnt give high enough (or low enough) options to deal properly with lith.
Using 100 daly and running 55v max.
Thoughts?